Moisture testing apparatus



Sept. 29, 1953 o. J. MORELOCK MOISTURE TESTING APPARATUS Filed Jan. 13,1951 III/II OLIVER .uuss MOREL oc/r mmvrox.

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SWITCH P08! T/ON Patented Sept. 29, 1953 MOISTURE TESTING APPARATUSOliver James Morelook, Short Hills, N. J assignor to Weston ElectricalInstrument Corporation, Newark, N. J a corporation of New JerseyApplication January 13, 1951, Serial No. 205,896

8 Claims.

This invention relates to apparatus useful for determining the moisturecontent of materials and more particularly to a set of rollers of novelconstruction and adapted to establish electrical contact with shelled,or unshelled, nuts passing therebetween, whereby the moisture content ofsuch nuts may be established by changes in the electrical conductivity.

At present there is no really satisfactory methed for determining themoisture content of nuts. It has been proposed to employ the dielectricmethod for such purposes but this is not satisfactory as the randompacking of the nuts, either whole or chopped, between the two plates ofthe dielectric apparatus results in great variations of readingaccuracy. Attempts have also been made to measure such moisture contentby the electrical conductivity method but thus far this has proven to beimpractical because of the irregular packing of the kernels and, moreimportantly, because such kernels are encased within an outer skin orhusk. Inasmuch as nuts have a high percentage of oil content it isimportant that the apparatus employed involves a minimum crushing actionif any practicable degree of actual moisture content is to be obtained.

This invention contemplates the provision of a set of rolls havingsplined surfaces of specific contour, thereby providing sharp cuttingedges that out into the nuts without crushing them and which make itpossible to test unshelled, as well as shelled, nuts with equal facilityand accuracy.

An object of this invention is the provision of a set of non-cloggingrolls suitable for use in testing shelled or unshelled nuts for moisturecontent with a minimum crushing action.

An object of this invention is the provision of a set of spaced rollsfor use with moisture testing apparatus, said rolls having splinedsurfaces terminating in aligned, sharp edges adapted to out into nutswithout crushing them.

An object of this invention is the provision of a set of spaced rollshaving longitudinally-extending knife edges capable of cutting throughthe shell and into the kernel of a nut passing therebetween to permitestablishment of electrical contact on opposite surfaces of the nut.

An object of this invention is the provision of a moisture tester fornuts comprising a pair of spaced rolls having knife edge surfaces, powermeans for rotating one of the rolls, means electrically insulating therolls from each other, a hopper for storing and directing nuts betweenon y,

2 the rolls, an electrical system connected to each of the rolls, andmeans indicating the magnitude of the current flow through the nutscontacted by the knife edge surfaces of the rolls.

These and other objects and advantages will be apparent from thefollowing description when taken with the accompanying drawings. Thedrawings are for purposes of illustration and are not to be construed asdefining the scope or limits of the invention, reference being bad forthe latter purpose to the appended claims.

In the drawings wherein like reference characters denote like parts inthe several views:

Figure 1 is an isometric view of apparatus made in accordance with thisinvention;

Figure 2 is a fragmentary, transverse sectional view of a roll showingthe formation of the teeth in the roll surface;

Figure 3 is a fragmentary, transverse section showing the teeth of therolls cutting into a peanut kernel;

Figure 4 is similar to Figure 3 and showing the action of the teeth onan unshelled peanut; and

Figure 5 illustrates an electrical circuit of the type suitable fordetermining the moisture content of nuts.

Referring now to Figure 1, the metallic roll it] is carried by a shaftI2 journaled for rotation in a pair of sleeve bearings carried bymetallic mounting brackets, one such bearing 14 and bracket [6 beingshown in the isometric view.. These brackets are secured rigidly, butadjust-- ably, to a frame 68 by screws 20 passing through; A second rollH is carried by its. shaft 53 that is journale-d for rotation insleevebearings 15, which bearings, however, are carthe slots 22.

ried by mounting brackets ll, made of insulating; material, secured tothe frame I9 by screws 24 passing through the frame into inserts 231nold-- ed in the brackets. The positioning of the roll it may beaccomplished by placing insulator shims 25 of the proper thickness,between the mounting brackets and the frame. Alternatively, theadjustable mounting of the follower roll may be accomplished in anysuitable manner. It will be apparent the roll H is electricallyinsulated from the frame and the roll it].

"Secured to the insulator mounting brackets I1 is a metal plate 3!] bymeans of the screws 3!. Sliding electrical contact with the roll I! isachieved by the contact blade 32 secured to the metal plate lit? by thescrew 33. The contact blade '32 is made of spring material, such asPhosphor bronze, and such blade may be provided with a silver button 34to establish and maintain good electrical contact with the roll. It mayhere be pointed out that the roll ll ma be connected to the electricalcircuit by securing a wire under the screw 33 or by soldering such wiredirectly to the blade 32. On the other hand, the roll l may be connectedinto the circuit by attaching a wire to any portion of the frame.Alternatively, such later contact may be made directly with the roll I0by a contact blade, similar to the blade 32 but carried by the mountingbracket IS.

The two frame members 18, I 9 are suitably, and rigidly, secured to abase to having anopening 4| therein, and such frame .members'support thetop 42 carrying the .hop'pers43u Itis apparent that nuts placed into thehopper will be directed to the space between the two rolls which havesplined surfaces of identical and specific contour.

Reference is now made to Figure 2 which is a fragmentary, transverseview of the roll it showing the construction of the teeth. Thedimensions given are for a-roll having a diameter of approximately 3inches. It-will be noted that the root of the individual teeth has anangle of 90 and'that'the side-wall of each-tooth inclines at an angle of9 from the radial line. When two rolls-havingsuch identical teethformations, are spaced "apart (see Figure 1) the adjacent teethare'oppositelydisposed and there is thus provided substantially alignedknife edges runninglongitudinally'the length of the rolls.

As statedhereinabove, the roll His power driven, preferably by'anelectric motor. The precise positioning of the roll ID' is set at thefactory'and, normally; no further adjustment thereof need bemadebytheuser. However, the; actual spacing between the two rolls issetbythe user in accordance with the'specific grade and specie ofnuts' tobe tested. Such spacing isaccomplished by inserting shims of the properthickness under the mounting brackets associated with the'roll H. -A setof shims'is furnished by the manufacturer, each shim having a precisethickness and appropriately marked so that the user will know whichshim, or shims, to insert for each product specie and grade. Whenthe'spacing -between the two rolls is so set, nuts of that-particulargrade and specie can pass between the'rolls onlywhen the; sharp,longitudinally-extending"knife edges of the roll surfaces cut partiallyinto the nuts.

The cutting action of the rolls-is illustrated in the fragmentary viewof Figure 3whichlllustrates the opposed teeth 50, l cutting into thepeanut kernel 52. It is understood-that when the rolls have an axiallength of; say, four inches, and the hopper opening, longitudinallyrelative to the rolls, is somewhat shorter, say, three inches, aplurality of kernels will be engaged by the opposed knife edges. Thus,theelectrical circuit between the insulated rolls is bridged; or closed,by such kernels as are cut 'into'by the knife edges of the teeth. If therolls are connected to an electrical circuit a current wil-lfiow andsuch current may be translated into moisture content of thenutsgraspedbetween-the two 'rolls. 'Further', although the-single roll [0 is powerdriven,'the roll II will rotate as the kernels are grasped between theknife edges. It should be noted that the teeth are so disposed relativeto the 'roll rotationthat the cutting action-into the kernel-and,likewise, rotation of the idler roll II, are facilitated. Specifically,the radially-extending wall of the tooth 50, onthe power-driven roll,forces the nut against the radially-extending wall of the tooth 5| ofthe idler roll. Inasmuch as these walls of the teeth are oppositelydisposed, relative to the downward movement of the nut therebetween, apositive biting action takes place.

Figure 4 is similar to Figure} butshowing an unshelled .peanut passingbetween' the rolls. If such unshelled peanuts are of the same grade and.species as that of the kernel shown in Figure 3,

the spacing between the rolls remains unchanged.

Consequently, the shell is crushed but the kernel remains whole, exceptfor the cuts made by the'knifeedg e's. In either case, the depth of ipenetration of the roll teeth into the kernel is substantially less thanthe transverse diameter of the kernel, whereby the kernel remains wholeand there is no oil diffusion and no crushed nut meat to clog the rolls.

Figure 5 illustrates an electrical circuit suitable for use with mynovel rolls to determinelthe moisture content of the nuts passingtherebetween. The rolls H], II are connected to the center blades of adouble pole-double throw switch 55, the roll 10 being driven'by thenotor 55. Electrical energy is supplied by a suitable constant source,such as the battery?! connected into the circuit through a switch 8 andthe current-limiting resistors 59, 60. The indicating instrument 6|,which mayhave a scale calibrated directly in terms of moisture content,is connected. across a series of fixed range-adjusting resistors 62 to19, inclusive, through the adjustable resistor l'l. One side ofthe'switch 55 is shunted by a calibrated resistor 12 connected to apredetermined point on the series of reslstors 62 1:0-10. When theswitch 5 5 is'thrown to the upper position current flows from thebattery through the lead-1 3, the calibrated resistor '.'2, the seriesresistors'68, 69,-10, the ,instrument, adjustable resistor H, resistor59 and switch 58. Under this condition the resistor II is adjusted toprovide top scale deflection of the instrument pointer. The switch 55 isthen thrown to the lower position, wherery the rolls I 0, II aresubstituted into the circuit for the calibrated resistor l2 and thecircuitto the indicating instrument is completed by the resistance ofthe nuts grasped between the two rolls, and, consequently, theinstrument pointer will deflect to some position determined by theelectrical conductivity of the nuts. By properly calibrating theinstrument scale, the pointer indication can be made to read per centmoisture content directly. Alternatively, the instrument scale may becalibrated in terms of current or conductance, which factors may beconverted to per cent moisture content by reference to a suitabletabulation as is well known in this art. The switch 13- manuallysettable to a selected point alonjrthe series of resistors 6210 servesto change the range of indicating instrument.

By driving the roll ID by means of an electrical motor a continuousmoisture testing of nuts, placed into the hopper, may behad. Inaddition, a-hand crank may be associatedwith one of the rolls, whichcrank will permit manual rotation lot the roll afixed distance to obtaina steady reading of the current flowing;through s uch kernels as areengaged by the opposed knife-edges. This feature is of practicalsignificance asit affords the operator a-means of, establishing thecorrect setting-of the instrument range'changing switch in accordancewith -the average moisture content of'the particularbatch of nuts beingtestedf Having now described my invention, it will be apparent theopposed, sharp edges of the longitudinal splines on the rolls affordsgood electrical contact with the nuts passing between the rolls withoutcrushing the nuts. Extensive tests have proven the suitability of suchapparatus for testing peanuts, pecans, and almonds, either shelled orunshelled, and that the roll surfaces are sufficiently self cleaning tooperate for long periods of time with no attention. While I havedescribed my invention with specific reference to the testing of nuts,those skilled in this art Will realize the apparatus is suitable fordetermining the moisture content of other products and/or materialshaving a finite shape such as coflfee beans, seeds, etc.

I claim:

1. In moisture testing apparatus of the type comprising a pair of spacedrolls for establishing electrical contact with nuts passingtherebetween, the improvement comprising discreet,longitudinally-extending, circumferentially-spaced, point ed teethformed in the surface of each roll, the individual teeth in each rollhaving a triangular cross section defined by a relatively shallow wallextending radially of the roll and a relatively long wall extendingperipherally of the roll, and the teeth of each roll being reverselydisposed relative to each other in the space between the rolls.

2. The invention as recited in claim 1, wherein the radially-extendingwall of each tooth forms an angle of approximately 9 degrees with thetrue radial line of the roll, and the root angle between such wall andthe adjacent wall is approximately 90 degrees.

3. The invention as recited in claim 2, wherein the ratio between theperipheral length and the radial depth of each tooth is approximately 3.

4. In apparatus for establishing electrical contact with nuts for thepurpose of determining the moisture content thereof the combination of apair of spaced, rotatable rolls; longitudinallyextending, pointed teethcut in the surface of each roll, the individual teeth in each roll havina triangular cross section defined by a relatively shallow wallextending radially of the roll and a relatively long wall extendingperipherally of the roll and the teeth of the individual rolls beingreversely disposed relative to each other in the space between therolls; means electrically insulating the rolls from each other;manuallysettable means to adjust the spacing between said rolls; ahopper directing the flow of nuts placed therein to the space betweenthe rolls; a contact blade in sliding contact with one of said rolls;and power means driving one of said rolls.

5. The invention as recited in claim 4, wherein the radial wall of theindividual teeth forms an angle of approximately 9 degrees with the trueradial plane of the roll, and such wall forms an angle of approximatelydegrees with the other tooth wall.

6. The invention as recited in claim 4, wherein the ratio between thewidths of the two walls defining the individual teeth is approximately3.

7. Apparatus for determining the moisture content of nuts and the likecomprising a supporting frame of metal; aligned metallic bracketsadjustably secured to the frame; a first roll rotatably supported bysaid metallic brackets, said roll having a splined surface; alignedinsulator brackets removably secured to the said frame; a second rollrotatably supported by said insulator brackets, said second roll havinga splined surface identical to that of the first wall and spacedtherefrom; a contact blade in slidable contact with the end of thesecond roll; power means for rotating the said first roll; a hoppercarried by the frame, said hopper directing the flow of nuts placedtherein to the space between the two rolls; an electrical networkincluding a source of electrical energy and an indicating instrumentcali-- brated in terms of moisture; a standardizing resistor selectivelyinsertable into the electrical network to establish a predeterminedindication of the instrument; and a double-pole, doublethrow switchhaving one movable blade connected to the first roll and the othermovable blade connected to the contact blade associated with the secondroll.

8. The invention as recited in claim 7, wherein the splines on theindividual rolls are oppositely disposed relative to each other at theadjacent roll surfaces.

OLIVER JAMES MORE'LOCK.

References Cited in the file of this patent UNITED STATES PATENTS

